<s>
The	O
Bendix	B-Device
G-15	I-Device
is	O
a	O
computer	O
introduced	O
in	O
1956	O
by	O
the	O
Bendix	O
Corporation	O
,	O
Computer	O
Division	O
,	O
Los	O
Angeles	O
,	O
California	O
.	O
</s>
<s>
The	O
G-15	O
has	O
a	O
drum	B-General_Concept
memory	I-General_Concept
of	O
2,160	O
29-bit	O
words	O
,	O
along	O
with	O
20	O
words	O
used	O
for	O
special	O
purposes	O
and	O
rapid-access	O
storage	O
.	O
</s>
<s>
The	O
chief	O
designer	O
of	O
the	O
G-15	O
was	O
Harry	O
Huskey	O
,	O
who	O
had	O
worked	O
with	O
Alan	O
Turing	O
on	O
the	O
ACE	B-Device
in	O
the	O
United	O
Kingdom	O
and	O
on	O
the	O
SWAC	B-Device
in	O
the	O
1950s	O
.	O
</s>
<s>
The	O
G-15	O
was	O
inspired	O
by	O
the	O
Automatic	B-Device
Computing	I-Device
Engine	I-Device
(	O
ACE	B-Device
)	O
.	O
</s>
<s>
It	O
is	O
a	O
serial-architecture	B-Device
machine	I-Device
,	O
in	O
which	O
the	O
main	O
memory	O
is	O
a	O
magnetic	B-General_Concept
drum	I-General_Concept
.	O
</s>
<s>
Even	O
the	O
machine	O
's	O
accumulators	B-General_Concept
are	O
implemented	O
as	O
drum	O
lines	O
:	O
three	O
double-word	O
lines	O
are	O
used	O
for	O
intermediate	O
storage	O
and	O
double-precision	O
addition	O
,	O
multiplication	O
,	O
and	O
division	O
in	O
addition	O
to	O
a	O
one	O
single-word	O
accumulator	O
.	O
</s>
<s>
This	O
use	O
of	O
the	O
drum	O
rather	O
than	O
flip-flops	B-General_Concept
for	O
the	O
registers	O
helped	O
to	O
reduce	O
vacuum	O
tube	O
count	O
.	O
</s>
<s>
A	O
consequence	O
of	O
this	O
design	O
was	O
that	O
,	O
unlike	O
other	O
computers	O
with	O
magnetic	B-General_Concept
drums	I-General_Concept
,	O
the	O
G-15	O
does	O
not	O
retain	O
its	O
memory	O
when	O
it	O
is	O
shut	O
off	O
.	O
</s>
<s>
The	O
adders	O
work	O
on	O
one	O
binary	O
digit	O
at	O
a	O
time	O
,	O
and	O
even	O
the	O
instruction	O
word	O
was	O
designed	O
to	O
minimize	O
the	O
number	O
of	O
bits	O
in	O
an	O
instruction	O
that	O
needed	O
to	O
be	O
retained	O
in	O
flip-flops	B-General_Concept
(	O
to	O
the	O
extent	O
of	O
leveraging	O
another	O
one-word	O
drum	O
line	O
used	O
exclusively	O
for	O
generating	O
address	O
timing	O
signals	O
)	O
.	O
</s>
<s>
Its	O
magnetic	B-General_Concept
drum	I-General_Concept
memory	I-General_Concept
holds	O
2,160	O
words	O
of	O
twenty-nine	O
bits	O
.	O
</s>
<s>
Average	B-General_Concept
memory	I-General_Concept
access	I-General_Concept
time	I-General_Concept
is	O
14.5	O
milliseconds	O
,	O
but	O
its	O
instruction	O
addressing	O
architecture	O
can	O
reduce	O
this	O
dramatically	O
for	O
well-written	O
programs	O
.	O
</s>
<s>
While	O
there	O
is	O
an	O
optional	O
high-speed	O
paper	O
tape	O
punch	O
(	O
the	O
PTP-1	O
at	O
60	O
digits	O
per	O
second	O
)	O
for	O
output	O
,	O
the	O
standard	O
punch	O
operates	O
at	O
17	O
hex	O
characters	O
per	O
second	O
(	O
510	O
bytes	B-Application
per	O
minute	O
)	O
.	O
</s>
<s>
Optionally	O
,	O
the	O
AN-1	O
"	O
Universal	O
Code	O
Accessory	O
"	O
included	O
the	O
"	O
35-4	O
"	O
Friden	B-Application
Flexowriter	I-Application
and	O
HSR-8	O
paper	O
tape	O
reader	O
and	O
HSP-8	O
paper	O
tape	O
punch	O
.	O
</s>
<s>
A	O
symbolic	O
assembler	O
,	O
similar	O
to	O
the	O
IBM	B-Device
650	I-Device
's	O
Symbolic	B-Application
Optimal	I-Application
Assembly	I-Application
Program	I-Application
(	O
SOAP	O
)	O
,	O
was	O
introduced	O
in	O
the	O
late	O
1950s	O
and	O
includes	O
routines	O
for	O
minimum-access	O
coding	O
.	O
</s>
<s>
Other	O
programming	O
aids	O
include	O
a	O
supervisor	O
program	O
,	O
a	O
floating-point	B-Algorithm
interpretive	O
system	O
named	O
"	O
Intercom	O
"	O
,	O
and	O
ALGO	B-Language
,	O
an	O
algebraic	O
language	O
designed	O
from	O
the	O
1958	B-Language
Preliminary	I-Language
Report	I-Language
of	O
the	O
ALGOL	B-Language
committee	O
.	O
</s>
<s>
Floating-point	B-Algorithm
arithmetic	I-Algorithm
is	O
implemented	O
in	O
software	O
.	O
</s>
<s>
The	O
"	O
Intercom	O
"	O
series	O
of	O
languages	O
provide	O
an	O
easier	O
to	O
program	O
virtual	O
machine	O
that	O
operates	O
in	O
floating	B-Algorithm
point	I-Algorithm
.	O
</s>
<s>
The	O
G-15	O
is	O
sometimes	O
described	O
as	O
the	O
first	O
personal	B-Device
computer	I-Device
,	O
because	O
it	O
has	O
the	O
Intercom	O
interpretive	O
system	O
.	O
</s>
<s>
The	O
title	O
is	O
disputed	O
by	O
other	O
machines	O
,	O
such	O
as	O
the	O
LINC	B-Device
and	O
the	O
PDP-8	B-Device
,	O
and	O
some	O
maintain	O
that	O
only	O
microcomputers	O
,	O
such	O
as	O
those	O
which	O
appeared	O
in	O
the	O
1970s	O
,	O
can	O
be	O
called	O
personal	B-Device
computers	I-Device
.	O
</s>
<s>
A	O
Bendix	B-Device
G-15	I-Device
was	O
used	O
at	O
Fremont	O
High	O
School	O
(	O
Oakland	O
Unified	O
School	O
District	O
)	O
in	O
the	O
1964-65	O
school	O
year	O
for	O
the	O
senior	O
seminar	O
math	O
class	O
.	O
</s>
<s>
A	O
Bendix	B-Device
G-15	I-Device
was	O
still	O
in	O
use	O
for	O
the	O
UC	O
Berkeley	O
extension	O
summer	O
class	O
in	O
programming	O
,	O
at	O
Oakland	O
Technical	O
High	O
School	O
,	O
in	O
1970	O
.	O
</s>
